This research will be exploratory, generating conceptual and analytical support for setting priorities for preventive and therapeutic interventions for individuals with multiple chronic conditions. With a focus on the delivery of care, timing, and coordination of services for individuals with multiple chronic conditions, and the relationship of these services to outcomes, this study should improve our understanding of the efficacy of interventions across the multidimensional spectrum of patient complexity. This work will also guide the conceptualization of how comorbidity and complexity can be valuable in directing clinical care and measurement. A better understanding of measurement of the quality of care in complex patients is essential to development and promulgation of care improvement mechanisms for this important group of patients. [unreadable] [unreadable] We propose secondary data analyses of five different clinically detailed data sets developed by the research team. They have been selected because analyses show better processes of care are associated with better outcomes. We now propose to conduct new analyses to elucidate the extent to which comorbidities and age influence the observed relationships between processes and outcomes. Specific aims include: [unreadable] [unreadable] Aim 1: To analyze how quality of care process scores vary as a function of comorbidities within and across study data sets. This analysis will consider various configurations for qualitatively and quantitatively characterizing comorbidities including depression. [unreadable] [unreadable] Aim 2: To analyze how care process scores vary as a function of other patient characteristics (including age and sociodemographics), other aspects of burden of illness (health status) and use of services (clinical visits to providers, number of providers, number of medications). [unreadable] [unreadable] Aim 3: For outcomes with a measurable link to process, to analyze the modifying effect on the process-outcome link of comorbidity, patient characteristics, and use of services. [unreadable] [unreadable] Aim 4: To develop strategies to refine quality measures for patients with multiple comorbidities and other aspects of complexity to promote care processes that are most beneficial to patients. [unreadable] [unreadable] This work aims to make explicit the consequences of applying recommendations designed for individual diseases to patients with multiple conditions. As such, we expect this work will foster better integration of services for patients with multiple comorbidities, improve provider and patient abilities to make informed decisions about health care choices, and help policy makers identify better ways to measure and promote quality care for complex patients. [unreadable] [unreadable] [unreadable] [unreadable]